[pakuchn]

Kevin,

I agree, why not just go with the K-x, it sounds like the right things to do. This is why I was talking with you all and reading about these two camera's because I wanted to learn what will I get for the $500 more by going with the K-7.

I think going with the K-x and getting quality lens and flash will be the way to go. I do have the money to get a K-7, so money is not the object, but from MOST, not all, but most of the reviews and people say that K-x deliver better image quality pictures compared to K-7. To be it’s just ridicules that Pentax sells a K-7 and the unit provides less quality images.

[LeDave]

Kevin,

I agree, why not just go with the K-x, it sounds like the right things to do. This is why I was talking with you all and reading about these two camera's because I wanted to learn what will I get for the $500 more by going with the K-7.

I think going with the K-x and getting quality lens and flash will be the way to go. I do have the money to get a K-7, so money is not the object, but from MOST, not all, but most of the reviews and people say that K-x deliver better image quality pictures compared to K-7. To be it’s just ridicules that Pentax sells a K-7 and the unit provides less quality images.

The K-x does not deliver better IQ than the K-7, it delivers significantly better high ISO IQ over the K-7. But the fact that the K-7 has a real ISO 100, means that in actuality the K-7 has better IQ over the K-x. But over that period if you increase the ISO, the K-x takes over. In terms of comparing IQ at the highest possible settings which means ISO 100 for K-7, while using the K-x's ISO 200 or synthetic ISO 100 to achieve the greatest amount of IQ in the best available lighting conditions for both cameras, the K-7 is where it wins.

The sensor used in the K-x is removed from true ISO 100 which gives it the power it needs to boast a significantly clean high ISO IQ, ISO 100 uses a ton of a sensor's potential high ISO output; and therefore if the K-7's Samsung sensor is stripped of ISO 100 in order to increase high ISO, it's high ISO would be significantly higher. But the K-7 needs that ISO 100 either way in order to attract more professionals who are in need of that ISO 100, and Pentax wants to market the K-7's image as professional.

[UnknownVT]

But the K-7 needs that ISO 100 either way in order to attract more professionals who are in need of that ISO 100, and Pentax wants to market the K-7's image as professional.

Hmmm...

Would you agree that the Nikon D3S and D700 are aimed at the professional market?

Both these have base ISO at 200
and ISO100 is only available as expanded range.

[LeDave]

Hmmm...

Would you agree that the Nikon D3S and D700 are aimed at the professional market?

Both these have base ISO at 200
and ISO100 is only available as expanded range.

Yes but they are full frames using a larger sensor, so even at expanded ISO 100, it would probably achieve the same IQ and if not better than APS-C sensors at it's true ISO 100

[UnknownVT]

Yes but they are full frames using a larger sensor, so even at expanded ISO 100, it would probably achieve the same IQ and if not better than APS-C sensors at it's true ISO 100

OK if we are restricting ourselves to APS-C size then -
how about the latest Nikon D300S (and even the original D300)?
both top of the line APS-C Nikons - again aimed probably more so than the K7 at professionals.....

The D300S and D300 base ISO is also 200 -
with only ISO100 reached as an expanded range.....

[LeDave]

OK if we are restricting ourselves to APS-C size then -
how about the latest Nikon D300S (and even the original D300)?
both top of the line APS-C Nikons - again aimed probably more so than the K7 at professionals.....

The D300S and D300 base ISO is also 200 -
with only ISO100 reached as an expanded range.....

Haha, I feel like I'm speaking for Pentax themselves now, jeeze what did I put myself into. But my next excuse would be that because the K-7 is advertised as Pentax's top of the line and flagship camera, they need the K-7 to have ISO 100 to show it's professionalism. While although the D300S doesn't have a natural ISO 100, it's not Nikon's flagship although top APS-C.

[UnknownVT]

Haha, I feel like I'm speaking for Pentax themselves now, jeeze what did I put myself into. But my next excuse would be that because the K-7 is advertised as Pentax's top of the line and flagship camera, they need the K-7 to have ISO 100 to show it's professionalism. While although the D300S doesn't have a natural ISO 100, it's not Nikon's flagship although top APS-C.

LoL! -
Sorry didn't mean to give you a hard time -
I have often wondered about ISO200 being the base ISO for many dSLRs.

Surely it's more to do with the chip/sensor design
than any manufacturer's marketing/policy?

Don't Nikons use Sony CMOS -
as suspected does the Kx?
whereas the K7 uses a Samsung chip?

[LeDave]

LoL! -
Sorry didn't mean to give you a hard time -
I have often wondered about ISO200 being the base ISO for many dSLRs.

Surely it's more to do with the chip/sensor design
than any manufacturer's marketing/policy?

Don't Nikons use Sony -
as is suspected for the Kx?
whereas the K7 uses a Samsung chip?

I don't believe all Nikons use a Sony sensor, they might have some in-house built sensors also but I could be wrong. But most Nikons as far as I can tell use Sony sensors, such as the D90, D5000, and D300, which all share the same Sony sensor. Yes the K-7 uses a Samsung sensor, the same one used in the K20D but optimized for faster readout with 4 channels instead of 2, as well as added FPS.

I also think that most camera manufacturers will start switching to sensors with a base of ISO 200 now due to the high success they have for high ISO. With it's significantly better high ISO, it outweighs the need and performance for ISO 100. In the end high ISO is harder to process than low ISO, so overall post-processing an image with ISO 200 to look like ISO 100 is cake compared to trying to process an image of ISO 800 to look like 600 or 400.

[UnknownVT]

the D90, D5000, and D300, which all share the same Sony sensor.

There you go
- thank you for that explanation/clarification.

The reason why those Nikons and the Pentax Kx all have base ISO200 -
is that they all are probably using the same CMOS Sony chip....
and the K7 has base ISO100 is because it uses the same Samsung chip as the K20D....

so what's all the clamoring for the Kx chip in the K7 about -
if the K7 already has superior IQ to the Kx?

[LeDave]

so what's all the clamoring for the Kx chip in the K7 about -
if the K7 already has superior IQ to the Kx?

I editted my post above yours, possibly due to the ease of post-processing. You can read that now. Also for some people who don't know how to post-process or are limited in that ability, they would want to take a picture in high ISO without having to go through all that hassle trying to process the image too much.

[UnknownVT]

I editted my post above yours, possibly due to the ease of post-processing. You can read that now.

Thank you again...

but then Canon bucks the trend -
as their dSLR CMOS sensors all seem to have base ISO100 -
with some "expanded" ISO50 on full-frames.....

[LeDave]

Thank you again...

but then Canon bucks the trend -
as their dSLR CMOS sensors all seem to have base ISO100 -
with some "expanded" ISO50 on full-frames.....

I don't know, I suppose everybody is different. Maybe in 2010, Canon will start releasing bodies with sensors with a base ISO of 200. Maybe it's their ISO 100 that is similar to 200 and 50 is similar to 100 in comparison to Sony sensors, not quite sure but oh well. So much comparison and contrast in ISO and cameras nowadays, people tend to argue so much about which camera is better in high ISO that they no longer spend that time to talk about photos instead. My dad told me that when he was younger, he had a Konica Minolta and one of his friend had a Pentax and his other friend had a Canon, and they would all go out and shoot pictures together for fun.

[pakuchn]

LeDave and UnknowsVT,

What model camera do you own?

[er1kksen]

For what it's worth, the K-x doesn't give up much (if anything) at ISO 100. I find that's where I get my best results. Still plenty of highlight range to recover, equal IQ in the normal tones to ISO 200, and somehow even cleaner shadows than ISO 200 (which is already great). In some ways the K20D feels better at ISO 100 (more "organic" feel to the images, slightly greater detail, better color imo) but the K-x is not at all far behind; the files are more seemingly "robust" and tolerate a great deal of manipulation. It's also easier to "rescue" an incorrect exposure.

The notion that artificial low ISOs are inferior to native ISOs may be becoming outdated; lumolabs found something funny about the histograms for ISO 100 that suggested that there was something more at play than the usual algorithms that lead to decreased DR.

[er1kksen]

Got any evidence? No one else is talking about two stops that I've seen.

Nope. I don't shoot test charts. My statements are purely anecdotal, and I have never claimed otherwise.

fwiw, it seems that my old RAW converter really wasn't doing the K20D any favors, as I just ran some K20D RAWs through lightroom and they look quite a bit better there. Now decent ISO 1600 exposures look pretty good, similar to 3200 with the K-x. The difference still holds true for exposures in crappy light with lots of shadows: the K20D shadows block up and get very noisy while the K-x can take an increase in brightness (even at 3200) while still producing a good image.

For example this was brightened by about a stop (among other alterations) and even with no luminance NR it's good enough for an 11x14 to my eyes.
Chelstache